Web feed device for rotary printing press



Feb. 27, 1962 i P. ZERNOV wEB FEED DEVICE FOR ROTARY PRINTING PR SSFiled Jul 11, 1960 3 Sheets-Sheet 1 m m m m PE 7-5.2 Zane/v0 & I

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Feb. 27, 1962 P. ZERNOV WEB FEED DEVICE FOR ROTARY PRINTING PRESS FiledJuly 11, 1960 5 SheetsP-Sheet 2 W h I-llllllllll m 1. V 1 \\N #1:||L-||||I ELEV FLIHHE L I llllllllll ll Feb. 27, 1962 P. ZERNOV WEB FEEDDEVICE FOR ROTARY PRINTING PRESS Filed July 11, 1960 s Sheets-She er. :s

INVENTOR. er-s2 Zea/vb States The present invention relates to a line ofprinting presses which employ a plurality of printing cylinders overwhich the web to be printed passes.

In in-line presses of the type to which this invention relates, forexample, rotogravure presses, the only places to create or establishtension in the web which is moving through the machine is at the entryand discharge ends of the line of presses. That is to say, the amount oftension in the web must be established at the incoming and outgoingsides of the line. Developing this tension may be done conventionally inseveral way. For example, the supply roll may be braked and the rewinderat the discharge side may pull sufficiently to create the desiredtension. Alternatively, power driven feed rolls may be used at the entryand discharge sides of the line. In any event, Where several presses areused in line, the web in the presses is of considerable length, being asmuch as thirty feet long between each pair of adjacent presses. Thislength of web creates difiiculties in properly distributing the tensionthroughout the length of the web, particularly in the middle portion ofthe web, that is, in the more centrally located presses. Statedotherwise, in conventional press lines, 'very little tension may be leftin the more central portion of the web length.

in in-line presses, the entire line eventually can be adjusted tooperate at a fairly balanced condition and when this equilibriumcondition exists, the various printing cylinders are in good registry.This balanced condition, however, is easily upset due to many variables,such as, inter alia, web shrinkage due to the action of the driers,variable tension of the incoming web, variable elasticity of the webalong its length, and changes in humidity and temperature. It is thennecessary to reestablish the opcrating equilibrium of the presses, andthe length of time required to do this is reflected in the amount ofmisregistry and the length of time during which this misregistryoccurred.

Furthermore, due to even very slight dillerences in the circumferentialsize of the various printing cylinders arrayed in an in-line press,there exists a difference in the elocity of the web at the differentprinting couples, that is, at the different locations where the printingactually takes place in the line. This difference in printing cylinderscircumferential sizes exists notwithstanding the painstaking efforts toproduce cylinders of identical sizes. For example, the dimensions of thebest pairs of matched cylinders may vary as much as three thousandths ontheir circumference. This variation in web velocity throughout itslength is possible because of the variation in tension of the web cominginto and leaving the point of printing.

In accordance with the present invention, a plurality of printingpresses have been provided in which the velocity of the web as it movesthrough the line of presses is maintained constant throughout itslength.

More particularly, the line of presses provided by the present inventionhas a series of power driven carrier rolls for supporting the web, whichrolls are driven at an ideal or average velocity that is desired to bemaintained in the line. The driven carrier rolls provided by the presentinvention furnish enough drive to the web to overcome the inherentinertia in the moving parts of the presses, and the web does not drivethese carrier rolls. In other words, a delicately balanced condition isprovided between the EfiZZEZ? Patented Feb, 2?, i362 driven carrierrolls and the web so that the rolls regulate the speed of the web. Byfurnishing some drive assist by means of the driven carrier rolls, andthereby relieving the Web of carrying and driving these inertia andfriction loads of the machine, it is possible to be able to consistentlyprint on low tensile strength material such as extensible webs of thecellophane, mylar or polyethlene type, and material as light as twentypound paper.

By means of the present invention, power driven carrier rolls provideweb tension and the tension is more evenly distributed throughout theline of presses.

An important aspect of the present invention is to provide a line ofpresses having power driven carrier rolls of the above type, in which aslip clutch is provided in the drive before the first carrier roll, bymeans of which clutch only enough torque is provided to overcome thedrag or inertia effects of the machine.

The present invention provides a line of printing presses in which aseries of power driven carrier rolls are spaced apart throughout theline, for example, preferably one roll for each printing cylinder. inthis manner the tension of the web is maintained in separate sections ofthe web length. Stated otherwise, the tension of the web is maintainedbetween each power driven carrier roll and its adjacent printingcylinders. Thus the several lengths of Web, through which the tension isseparately maintainable, are relatively short as compared to the entirelength of the web in the entire line of presses. As a result of theshorter length of web which must be controlled as to tension, it ispossible to get a much faster response or correction for each individualprinting cylinder. Regardlessot the signalling or correcting devicesused, they can perform their correction more quickly because they onlyneed to vary the web length between two adjacent web decks.

ermits a faster correcting response to reestablish balanced conditionsin the line because the tension changes can be made more quickly inthese shorter web lengths.

Furthermore, with the above arrangement, a much more stable press isprovided because when a variation is introduced into the line, abalanced condition will be reestablished faster. This is possiblebecause there has been provided several key references, one between eachprinting station, to effect constant velocity throughout the web lengthand permit each printing unit to find its balanced condition betweeneach set of power driven carrier rolls. One printing unit will notmaterially effect the one adjacent to it.

These and other objects and advantages of the present invention willappear as this disclosure progresses, reference being had to theaccompanying drawings, in which- FIGURE 1 is an elevational side view,taken from the operators side, of a portion of a printing press line,certain parts shown as being broken away, in section or removed, and theview being more orless aschematic showing;

FIGURE 2 is a detailed elevational view of a portion of the machineshown in FIGURE 1, certain parts being broken away; j

FIGURE 3 is a plan view of the machine shown in FIGURE 2, certain partsbeing in section or broken away;

FIGURE 4 is a fragmentary sectional view taken along line 44 in FIGURE1, but on an enlarged scale;

FIGURE 5 is a detailed elevational view taken generally from line 5-5 inFIGURE 4;

FIGURE 6 is a view taken generally along the line 66 in FIGURE 7, and;

FIGURE 7 is a sectional view taken along line 7-7 in FIGURE 6.

Referring in greater detail to the drawings, and parincludes thehorizontally disposed pair of beams or chan- The arrangement provided bythis invention thus.

nels I and 2 which are arranged in parallelism. The pairs of verticalsupports 3 hold the channels 1 and 2 above the floor F and over theseveral printing units A, B and C. The channels, vertical supports andpresses are all secured together as a complete line.

Only three printing units have been shown, but as many as eight areoften used together in a single in-line rotgravure operation, and theinvention is not limited to use with any particular number of presses.

Each of the presses A, B and C are substantially identical for purposesof this disclosure and each have, respectively, a printing cylinder Ca,Cb, and Cc which are suitably journalled for rotation in the side wallsof their respective presses in the well known manner. Each of theprinting cylinders may be driven from a common drive shaft 5 and withwhich they each have an adjustable running register 6. The cylinders arethereby each adjustable relative to the drive shaft and to one anotherfor registry purposes.

Each of the presses also has an impression roll 7 adjacent to itsprinting cylinder and the actual printing is done on the Web W as itpasses between the printing cylinder and the impression roll. A nipprinting couple is formed at these printing locations by the impressionroll which firmly presses the web against the cylinder.

A conventional overhead drier 8 having various supporting rollers forthe web may also form part of each press and the length of the webbetween adjacent printing cylinders may be about thirty feet in length.Thus in a line having eight presses, a web length of 250 to 300 feetwithin the complete line or" presses is not uncommon.

Other conventional idler rolls iii, 11 and 12 are provided forsupporting the web as it moves through the line.

At the entry side of the first press A, the web passes from a supplyroll and over various pre-feed rolls (not .shown) and then over theguide roll 13, and into the conventional infeed means if. This feedmeans includes a pair of idler rolls 14- and 15 between which is acenter driven roll 16 having a gear 16:; secured to its shaft that isdriven from the main drive of the machine through Worm 165 on shaft 5.This feed means acts to pull the web from the supply roll (not shown)and feed it at a precisely metered rate.

At the discharge end of the press line is located an outfeed means forthe web in the form of nip rolls 17 and 18, between which is located thedriven feed roll 19.

The infeed means and the outfeed means act to create tension in the weblocated in the press line. However, as previously indicated, thisgeneral tension may also be created in different ways and specific feedmeans may not be necessary. For example, the supply roll (not shown) atthe entry side of the press line may have means for creating a brakingaction; the rewinder (not shown) at the discharge side of the press linemay be controllably driven sufficiently to provide the desired tension.In any event it is necessary to provide means for creating, andmaintaining tension at the entry and discharge sides of the press line.

As theweb leaves the feed roll it passes through conventional dancerroll unit D which controls and maintains a certain tension in the web.at this location.

It can be seen that in the above line of presses there are aconsiderable number of moving parts, many of which have not beendescribed, which have considerable inertia and create friction losses,and'which are conventionally driven by the web. This imposes a heavyload on the web and variations in tension in the length of the Webwithin the line of presses.

In accordance with the present invention, power driven carrier rolls areprovided for the web, which rolls are spaced apart within the line ofpresses. The first of such rolls R1 is located just after the dancerassembly and is rotatably mounted between the channels '1 and 2.

The other power driven carrier rolls R2, R3. and R4, and theirrespective rubber covered nip rolls 20, 21 and 22 are similar and adescription of one set of each is deemed to be sufiicient. These rollsare also mounted between the channels 1 and 2 as will be more fullydescribed. It will be seen that a power driven roll is located betweeneach adjacent pair of printing cylinders and one before the firstcylinder Ca and one after the last cylinder Cc.

As will be fully described, the first roll R1 is driven from the mainpower source in the form of an electric motor M, and all of thesubsequent rolls are driven from a common line of power and right anglegear boxes. Thus all of the rolls R1 to R4 are driven together inunison.

Referring in greater detail to the first roll R1, an air operated slipclutch 25 is mounted on the operator end of the roll R1, as clearlyshown in FIGURE 4. More particularly, a stub shaft 26 is fastened by pin27 to the shaft 28 of the roll R1 and forms an extension thereof. Shaft26 is journalled in the bearing block 29 secured by bolt means St) tochannel 1.

The clutch 25 is of conventional design and it is believed sufficient tosay that shaft 26 is secured to one of its clutch elements, and a sleeve31 is secured to the other of its clutch elements. i Thus the shaft 26and sleeve 31 are engageable and disengageable with one another. Aclutch gear'32 is rigidly secured to sleeve 31 and is in constant meshwith gear: 31a supported on shaft 31b and fixed to the timing pulleySic. An endless timing belt 33 is trained over this pulley.

Power is transmitted to the clutch from the power driven center roll 16via a timing pulley and the belt 33 trained thereover. Idler pulleys(not shown) to regulate belt tension may be utilized in the conventionalmanner. In this manner the drive for the carrier rolls is taken directlyfrom the feed unit.

The clutch 25 is set so that only a predetermined speed is imparted tothe carrier rolls R1 to R4. By means of this clutch only enough torqueis provided to the carrier rolls to overcome mechanical losses in theline due to inertia, friction and other causes. Depending on the feedcharacteristics desired from the driven carrier rolls, and whether ornot feed means are used at the entry and discharge sides of the line,the carrier rolls may or may not be of the positive nip type. Severalvariations may be used. For example, a positive nip may be provided foreach carrier roll, no nip may be necessary for any of the carrier rolls,or a nip may be provided for only some of the carrier rolls.

In the illustration of the invention shown here, a positive nip isprovided for each carrier roll, as will appear.

A rubber covered nip roll 4% is provided for cooperation with roll R1and is adjustably mounted between channels 1 and 2 for shifting betweena nipping or closed position and a throw-out or open position.

As shown in FIGURES 2 and 3, the nip roll 40 is urged to the nippingposition by a pair of air operated members 44, one at each end of roll49, members are securely mounted to the main frame by bracket 45 andeach have a shiftable actuating rod 46 extending therefrom. The nip roll49 is swingably mounted on a pair of arms 47, one at each end of theroll (only one arm is shown), which arms are pivoted at their upper endon pins 48 to their respective channels. Actuating rods 46 are pivotedto their respective arm '47 and when extended act to swing the roll 4!)to the nipping position. Member 44 has a spring 44a by means of whichthe roll 40 is spring biased to the open position, the members 44 beingair operated in only one direction.

A manually operated handle 59 is used to actuate an air valve 51 tothereby cause air to be admitted to or released from members 44 viaconduit 52 and 53, a central valve 54 regulated by the knob 55 is usedto meter the air from the supply line 56 to the control valve 51. Theoperator can readily adjust the nippingpressure on roll R1 and alsocompletely open the nip roll 46.

The; structure, drive and operation of the other carrier rolls R2, R3,and R4 and their nip rolls will now be described, reference being madeonly to the second roll R2 but it being understood that the other rollsare similar.

Referring in particular to FIGURE 3, the shaft 60 of R2 is journalled inthe pillow blocks 61 and 62 securely mounted on channels 1 and 2,respectively. A bevel gear 63 is secured to the outer end of shaft 60.

The drive between the carrier rolls is as follows. A right angle gearbox 64 is located at the back end (as viewed in FIGURE 1) of the rollR1, that is, on the side opposite to the operators side. A drive tube 65extends from this box 64 to another right angle gear box 66 located atthe rear end of roll R2. Another drive tube 67 extends from box 66 to athird right angle gear box 68 located at the end of roll R3. Suitablecouplings 70 connect the drive tubes to the gear boxes.

Within each of the gear boxes is a bevel gear 71 which is in constantmesh with the bevel gear carried on the end of each of the adjacentcarrier roll shafts. The gear 71 is fixed to a shaft 73 rotatablymounted in the box, which shaft is fixed to the drive tubes extendingfrom each end thereof, by key means 74. The various drive tubes and theshafts 73 may be considered as a single drive shaft.

The carrier rolls are thus all positively in synchronization with oneanother, deriving their power from the feed roll means 16.

The rubber covered nip roll 20 is mounted by its dead shaft 20asupported on the channels 1 and 2. A handle means 20b is secured to theend of shaft 201: for oscillating the latter between nipping and openpositions. Eccentric sleeves 20:: are fixed to the ends of shaft 20a andthese sleeves are rotatably mounted in the anti-friction bearing members20d secured to channels 1 and 2. By oscillating the handle means 20b,the entire shaft 20b and its roller 20 are shifted bodily toward andaway from the roll R2, and by simply throwing the handle in onedirection the roller 20 is thrown off of the nip position. The handleand eccentric arrangement is of the over-center type and the spring 20eloads the roller in the over-center position and firmly against the rollR2. The effective length of the moment arm through which the spring actsto load the roll is the amount of eccentricity of the eccentrics.

Rsum

By means of the power driven carrier rolls the actual length of the webin the line of presses is, figuratively speaking, broken down intoseveral separate lengths, which lengths are easily controlled andadjusted as to tension. Not only is a more uniform tension providedthroughout the length of the web but the tension at the 6 entry anddischarge sides of each printing cylinder is more nearly equalized.

The driving effect of the carrier rolls is sufiicient to relieve the webof a considerable load otherwise imposed upon it.

The velocity of the web is maintained constant through its length andcan be accurately controlled.

A much faster correcting response is possible and a more stableoperating press is provided.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claims particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

What is claimed and desired to be secured by'Letters Patent is:

1. A printing press line having a plurality of printing cylinders and animpression roll for each cylinder which forms a nip printing coupletherewith and through which a Web is adapted to pass, said lineralsohaving means adjacent its entry and discharge sides for creating tensionin the web in said line, a series of power driven carrier rolls spacedapart in said line for at least partially driving said web, meansdrivingly connecting said carrier rolls together so as to drive them insynchronization with one another, and a slip clutch for driving onepower driven carrier roll in the line whereby the maximum velocity ofsaid carrier rolls is limited to cause said rolls to deliver only apredetermined amount of torque to said web.

2. In a printing press line having a plurality of printing cylindersthrough which a web is fed, an impression roll for each of saidcylinders and forming a nip printing couple therewith, infeed means forthe web at the entry side of said line, outfeed means for said web atthe discharge sde of said line, said infeed and outfeed meansestablishing tension in the web therebetween, a series of power drivencarrier rolls for said web and located in spaced apart relation in saidline, and drive transmitting means for drivingly connecting said carrierrolls to said web infeed means whereby said carrier rolls are driven bysaid infeed means.

3. A device as set out in claim 2 including a slip clutch in said drivetransmitting means to limit the driving effect of said carrier rolls onsaid web to a predetermined value.

References Cited in the file of this patent UNITED STATES PATENTS1,581,151 Yetter Apr. 20, 1926 1,661,209 Wolf Mar. 6, 1928 2,809,582Crawford Oct. 15, 1957

